AP Chem Unit 2 nb

electromagnetic radiation

a form of energy that travels through space as oscillating electric and magnetic fields perpendicular to each other and to the direction of wave propagation

Types of radiation from lowest to highest wavelength

gamma rays, x-rays, ultraviolet rays, visible light (400-750 nm),infrared rays, microwave, radio

Limitations of Bohr Model

cannot explain bonding

only worked for hydrogen

e- don’t move in 2D orbit

Heisenberg’s Uncertainty Principle

it is impossible to know exact location and velocity of an electron at the same time

Wave particle duality

energy and matter (such as light and electrons) exhibit properties of both waves and particles

Atomic orbitals

areas of probability where we have a 90% chance of finding an e- (can hold max of 2 e-)

Principle Quantum # (n)

energy level, corresponds with row on PT (n=1-7)

Angular Momentum Quantum # (l)

shape/sublevel of orbital and corresponds with block on PT (l=0,1,2,3)

Magnetic Quantum # (m_L)

which orbital e- is in within sublevel (m_L=-l to +l)

Magnetic Spin Quantum # (M_s)

e- is spin up or spin down (-1/2 or +1/2)

Exceptions to normal configurations

column 4/9 of D block

isoelectronic

when atoms/ions have the same electron configuration

different species have same configuration

Metals

high thermal and electrical conductivity, a shiny reflective luster, and malleability

nonmetals

high electronegativity, high ionization energy, and a tendency to gain or share electrons, poor conductors

order of groups on PT

alkali metals, alkaline earth metals, _______, halogens, noble gases

bonding radius

half the distance between the nuclei of two identical adjacent bonded atoms

Effective nuclear charge (Zeff)

net charge felt by the valence e- from the nucleus

Zeff=Z-s

Z=nuclear charge (#protons)

S= shielding/core e-

Effective nuclear charge trend

down a column= constant

across period= increases

Atomic radius

radius of an atom

atomic radius trend

down a group= increases

across a group= decreases

ionic radius

radius of an ion compared to neutral version

ionic radius pattern

cations= smaller than neutral atom

anions= slightly larger than neutral atom

Ionization Energy

minimum amount of energy required to remove e- from atom

Ionization Energy Trend

down a column=decreases

across a period=increases

IE Exceptions

Nitrogen vs O

Be vs B

Electron Affinity

the energy absorbed or released when an atom gains an e-

Electron Affinity Pattern

metals: don’t want e- (EA=+)

nonmetals: want e- (EA=-)

noble gases: don’t want e- (EA=++++)